Inorganic Membranes Allow for a More Clever Use of Nanoparticles As CO2 Conversion Catalyst

An important challenge in the valorization of CO2 and H2 into fuels is the development of a stable, reusable and easy to handle heterogeneous catalyst. Here, a silica nanofibrous membrane is investigated as carrier for Ru nanoparticles, themselves encapsulated inside the metal organic framework Cr-MIL-101. The catalytic membrane is investigated for the Sabatier methanation reaction. The direct electrospinning of a tetraorthosilicate sol-gel system results in a highly thermal resistant silica nanofibrous structure (up to 1100°C) with a large amount of pores between the fibers in the µm-range, allowing a high gas throughput with low pressure requirements. A straightforward dip-coating procedure of the carrier was used to obtain a Ru@MIL-101 functionalized silica nanofibrous veil, avoiding Ru clustering. The obtained catalytic membrane exhibited an apparent turnover frequency of 3257 h-1 at 250°C. This system therefore paves the way towards structured reactors for efficient CO2 hydrogenation processes.